Comment #2 on issue 169 by [email protected]: probably incorrect treatment of negative expiration time
http://code.google.com/p/memcached/issues/detail?id=169
For me, using a value of -60 in a cas seemed to always expire immediately, but I probably never did it within 60 seconds of memcached startup. I was using this to implement compare and delete with cas for distributed locking.
This behavior changed in memcached version 1.4.4_461_gf99c147 (from membase). The keys set no longer expire immediately, and I'm not sure of when, if ever they do expire.
My workaround is to use an expiration in the past, that memcached will interpret as a unix time; eg. 2592001
